“This is a pretty strong assessment,” said John McLaughlin, who served as deputy director of the Central Intelligence Agency from 2000 to 2004. “The intelligence community does not say ‘high confidence’ about something unless they have really chewed it over.” Intelligence agencies state their findings in terms of high, medium, or low confidence.

Mr. McLaughlin said the term “high confidence” is not “used lightly” particularly since the 2003 Iraq intelligence failure. But he noted that the assessment includes a caveat that “high confidence” falls short of confirmation.

He said that confirmation, or indisputable evidence, of sensitive intelligence matters is rare, and in this case it could be physical samples or a confession by a regime official. “There is always some element, in this case small,” of uncertainty, he said…